Make model context window optional

[bhouston]

Description

Make the context window size for models optional, allowing models without a specified context window to fall back to undefined.

Changes

• Modified the LLMResponse interface to use contextWindow instead of maxTokens
• Updated provider implementations to handle undefined context windows
• Modified status updates and token usage tracking to work with or without a context window
• Removed automatic triggering of the compact tool when no context window is known

Motivation

This change allows the system to work with models that don't have a known context window size, making the system more flexible with custom or new models.

Implementation

• The changes have been made to several files in the agent package:
  • core/llm/types.ts
  • core/llm/providers/anthropic.ts
  • core/llm/providers/ollama.ts
  • core/llm/providers/openai.ts
  • core/toolAgent/statusUpdates.ts
  • core/toolAgent/toolAgentCore.ts

[bhouston]

completed and merged.